drivers/usb/serial/usb_wwan.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3   USB Driver layer for GSM modems
   4
   5   Copyright (C) 2005  Matthias Urlichs <smurf@smurf.noris.de>
   6
   7   Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>
   8
   9   History: see the git log.
  10
  11   Work sponsored by: Sigos GmbH, Germany <info@sigos.de>
  12
  13   This driver exists because the "normal" serial driver doesn't work too well
  14   with GSM modems. Issues:
  15   - data loss -- one single Receive URB is not nearly enough
  16   - controlling the baud rate doesn't make sense
  17 */
  18
  19 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
  20 #define DRIVER_DESC "USB Driver for GSM modems"
  21
  22 #include <linux/kernel.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/errno.h>
  25 #include <linux/slab.h>
  26 #include <linux/tty.h>
  27 #include <linux/tty_flip.h>
  28 #include <linux/module.h>
  29 #include <linux/bitops.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/serial.h>
  33 #include <linux/serial.h>
  34 #include "usb-wwan.h"
  35
  36 /*
  37  * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
  38  * in CDC ACM.
  39  */
  40 static int usb_wwan_send_setup(struct usb_serial_port *port)
  41 {
  42         struct usb_serial *serial = port->serial;
  43         struct usb_wwan_port_private *portdata;
  44         int val = 0;
  45         int ifnum;
  46         int res;
  47
  48         portdata = usb_get_serial_port_data(port);
  49
  50         if (portdata->dtr_state)
  51                 val |= 0x01;
  52         if (portdata->rts_state)
  53                 val |= 0x02;
  54
  55         ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
  56
  57         res = usb_autopm_get_interface(serial->interface);
  58         if (res)
  59                 return res;
  60
  61         res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
  62                                 0x22, 0x21, val, ifnum, NULL, 0,
  63                                 USB_CTRL_SET_TIMEOUT);
  64
  65         usb_autopm_put_interface(port->serial->interface);
  66
  67         return res;
  68 }
  69
  70 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
  71 {
  72         struct usb_wwan_port_private *portdata;
  73         struct usb_wwan_intf_private *intfdata;
  74
  75         intfdata = usb_get_serial_data(port->serial);
  76
  77         if (!intfdata->use_send_setup)
  78                 return;
  79
  80         portdata = usb_get_serial_port_data(port);
  81         /* FIXME: locking */
  82         portdata->rts_state = on;
  83         portdata->dtr_state = on;
  84
  85         usb_wwan_send_setup(port);
  86 }
  87 EXPORT_SYMBOL(usb_wwan_dtr_rts);
  88
  89 int usb_wwan_tiocmget(struct tty_struct *tty)
  90 {
  91         struct usb_serial_port *port = tty->driver_data;
  92         unsigned int value;
  93         struct usb_wwan_port_private *portdata;
  94
  95         portdata = usb_get_serial_port_data(port);
  96
  97         value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
  98             ((portdata->dtr_state) ? TIOCM_DTR : 0) |
  99             ((portdata->cts_state) ? TIOCM_CTS : 0) |
 100             ((portdata->dsr_state) ? TIOCM_DSR : 0) |
 101             ((portdata->dcd_state) ? TIOCM_CAR : 0) |
 102             ((portdata->ri_state) ? TIOCM_RNG : 0);
 103
 104         return value;
 105 }
 106 EXPORT_SYMBOL(usb_wwan_tiocmget);
 107
 108 int usb_wwan_tiocmset(struct tty_struct *tty,
 109                       unsigned int set, unsigned int clear)
 110 {
 111         struct usb_serial_port *port = tty->driver_data;
 112         struct usb_wwan_port_private *portdata;
 113         struct usb_wwan_intf_private *intfdata;
 114
 115         portdata = usb_get_serial_port_data(port);
 116         intfdata = usb_get_serial_data(port->serial);
 117
 118         if (!intfdata->use_send_setup)
 119                 return -EINVAL;
 120
 121         /* FIXME: what locks portdata fields ? */
 122         if (set & TIOCM_RTS)
 123                 portdata->rts_state = 1;
 124         if (set & TIOCM_DTR)
 125                 portdata->dtr_state = 1;
 126
 127         if (clear & TIOCM_RTS)
 128                 portdata->rts_state = 0;
 129         if (clear & TIOCM_DTR)
 130                 portdata->dtr_state = 0;
 131         return usb_wwan_send_setup(port);
 132 }
 133 EXPORT_SYMBOL(usb_wwan_tiocmset);
 134
 135 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
 136                    const unsigned char *buf, int count)
 137 {
 138         struct usb_wwan_port_private *portdata;
 139         struct usb_wwan_intf_private *intfdata;
 140         int i;
 141         int left, todo;
 142         struct urb *this_urb = NULL;    /* spurious */
 143         int err;
 144         unsigned long flags;
 145
 146         portdata = usb_get_serial_port_data(port);
 147         intfdata = usb_get_serial_data(port->serial);
 148
 149         dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
 150
 151         i = 0;
 152         left = count;
 153         for (i = 0; left > 0 && i < N_OUT_URB; i++) {
 154                 todo = left;
 155                 if (todo > OUT_BUFLEN)
 156                         todo = OUT_BUFLEN;
 157
 158                 this_urb = portdata->out_urbs[i];
 159                 if (test_and_set_bit(i, &portdata->out_busy)) {
 160                         if (time_before(jiffies,
 161                                         portdata->tx_start_time[i] + 10 * HZ))
 162                                 continue;
 163                         usb_unlink_urb(this_urb);
 164                         continue;
 165                 }
 166                 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
 167                         usb_pipeendpoint(this_urb->pipe), i);
 168
 169                 err = usb_autopm_get_interface_async(port->serial->interface);
 170                 if (err < 0) {
 171                         clear_bit(i, &portdata->out_busy);
 172                         break;
 173                 }
 174
 175                 /* send the data */
 176                 memcpy(this_urb->transfer_buffer, buf, todo);
 177                 this_urb->transfer_buffer_length = todo;
 178
 179                 spin_lock_irqsave(&intfdata->susp_lock, flags);
 180                 if (intfdata->suspended) {
 181                         usb_anchor_urb(this_urb, &portdata->delayed);
 182                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 183                 } else {
 184                         intfdata->in_flight++;
 185                         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 186                         err = usb_submit_urb(this_urb, GFP_ATOMIC);
 187                         if (err) {
 188                                 dev_err(&port->dev,
 189                                         "%s: submit urb %d failed: %d\n",
 190                                         __func__, i, err);
 191                                 clear_bit(i, &portdata->out_busy);
 192                                 spin_lock_irqsave(&intfdata->susp_lock, flags);
 193                                 intfdata->in_flight--;
 194                                 spin_unlock_irqrestore(&intfdata->susp_lock,
 195                                                        flags);
 196                                 usb_autopm_put_interface_async(port->serial->interface);
 197                                 break;
 198                         }
 199                 }
 200
 201                 portdata->tx_start_time[i] = jiffies;
 202                 buf += todo;
 203                 left -= todo;
 204         }
 205
 206         count -= left;
 207         dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
 208         return count;
 209 }
 210 EXPORT_SYMBOL(usb_wwan_write);
 211
 212 static void usb_wwan_indat_callback(struct urb *urb)
 213 {
 214         int err;
 215         int endpoint;
 216         struct usb_serial_port *port;
 217         struct device *dev;
 218         unsigned char *data = urb->transfer_buffer;
 219         int status = urb->status;
 220
 221         endpoint = usb_pipeendpoint(urb->pipe);
 222         port = urb->context;
 223         dev = &port->dev;
 224
 225         if (status) {
 226                 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
 227                         __func__, status, endpoint);
 228
 229                 /* don't resubmit on fatal errors */
 230                 if (status == -ESHUTDOWN || status == -ENOENT)
 231                         return;
 232         } else {
 233                 if (urb->actual_length) {
 234                         tty_insert_flip_string(&port->port, data,
 235                                         urb->actual_length);
 236                         tty_flip_buffer_push(&port->port);
 237                 } else
 238                         dev_dbg(dev, "%s: empty read urb received\n", __func__);
 239         }
 240         /* Resubmit urb so we continue receiving */
 241         err = usb_submit_urb(urb, GFP_ATOMIC);
 242         if (err) {
 243                 if (err != -EPERM && err != -ENODEV) {
 244                         dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
 245                                 __func__, err);
 246                         /* busy also in error unless we are killed */
 247                         usb_mark_last_busy(port->serial->dev);
 248                 }
 249         } else {
 250                 usb_mark_last_busy(port->serial->dev);
 251         }
 252 }
 253
 254 static void usb_wwan_outdat_callback(struct urb *urb)
 255 {
 256         struct usb_serial_port *port;
 257         struct usb_wwan_port_private *portdata;
 258         struct usb_wwan_intf_private *intfdata;
 259         unsigned long flags;
 260         int i;
 261
 262         port = urb->context;
 263         intfdata = usb_get_serial_data(port->serial);
 264
 265         usb_serial_port_softint(port);
 266         usb_autopm_put_interface_async(port->serial->interface);
 267         portdata = usb_get_serial_port_data(port);
 268         spin_lock_irqsave(&intfdata->susp_lock, flags);
 269         intfdata->in_flight--;
 270         spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 271
 272         for (i = 0; i < N_OUT_URB; ++i) {
 273                 if (portdata->out_urbs[i] == urb) {
 274                         smp_mb__before_atomic();
 275                         clear_bit(i, &portdata->out_busy);
 276                         break;
 277                 }
 278         }
 279 }
 280
 281 unsigned int usb_wwan_write_room(struct tty_struct *tty)
 282 {
 283         struct usb_serial_port *port = tty->driver_data;
 284         struct usb_wwan_port_private *portdata;
 285         int i;
 286         unsigned int data_len = 0;
 287         struct urb *this_urb;
 288
 289         portdata = usb_get_serial_port_data(port);
 290
 291         for (i = 0; i < N_OUT_URB; i++) {
 292                 this_urb = portdata->out_urbs[i];
 293                 if (this_urb && !test_bit(i, &portdata->out_busy))
 294                         data_len += OUT_BUFLEN;
 295         }
 296
 297         dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 298         return data_len;
 299 }
 300 EXPORT_SYMBOL(usb_wwan_write_room);
 301
 302 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
 303 {
 304         struct usb_serial_port *port = tty->driver_data;
 305         struct usb_wwan_port_private *portdata;
 306         int i;
 307         unsigned int data_len = 0;
 308         struct urb *this_urb;
 309
 310         portdata = usb_get_serial_port_data(port);
 311
 312         for (i = 0; i < N_OUT_URB; i++) {
 313                 this_urb = portdata->out_urbs[i];
 314                 /* FIXME: This locking is insufficient as this_urb may
 315                    go unused during the test */
 316                 if (this_urb && test_bit(i, &portdata->out_busy))
 317                         data_len += this_urb->transfer_buffer_length;
 318         }
 319         dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 320         return data_len;
 321 }
 322 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
 323
 324 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
 325 {
 326         struct usb_wwan_port_private *portdata;
 327         struct usb_wwan_intf_private *intfdata;
 328         struct usb_serial *serial = port->serial;
 329         int i, err;
 330         struct urb *urb;
 331
 332         portdata = usb_get_serial_port_data(port);
 333         intfdata = usb_get_serial_data(serial);
 334
 335         if (port->interrupt_in_urb) {
 336                 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 337                 if (err) {
 338                         dev_err(&port->dev, "%s: submit int urb failed: %d\n",
 339                                 __func__, err);
 340                 }
 341         }
 342
 343         /* Start reading from the IN endpoint */
 344         for (i = 0; i < N_IN_URB; i++) {
 345                 urb = portdata->in_urbs[i];
 346                 if (!urb)
 347                         continue;
 348                 err = usb_submit_urb(urb, GFP_KERNEL);
 349                 if (err) {
 350                         dev_err(&port->dev,
 351                                 "%s: submit read urb %d failed: %d\n",
 352                                 __func__, i, err);
 353                 }
 354         }
 355
 356         spin_lock_irq(&intfdata->susp_lock);
 357         if (++intfdata->open_ports == 1)
 358                 serial->interface->needs_remote_wakeup = 1;
 359         spin_unlock_irq(&intfdata->susp_lock);
 360         /* this balances a get in the generic USB serial code */
 361         usb_autopm_put_interface(serial->interface);
 362
 363         return 0;
 364 }
 365 EXPORT_SYMBOL(usb_wwan_open);
 366
 367 static void unbusy_queued_urb(struct urb *urb,
 368                                         struct usb_wwan_port_private *portdata)
 369 {
 370         int i;
 371
 372         for (i = 0; i < N_OUT_URB; i++) {
 373                 if (urb == portdata->out_urbs[i]) {
 374                         clear_bit(i, &portdata->out_busy);
 375                         break;
 376                 }
 377         }
 378 }
 379
 380 void usb_wwan_close(struct usb_serial_port *port)
 381 {
 382         int i;
 383         struct usb_serial *serial = port->serial;
 384         struct usb_wwan_port_private *portdata;
 385         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 386         struct urb *urb;
 387
 388         portdata = usb_get_serial_port_data(port);
 389
 390         /*
 391          * Need to take susp_lock to make sure port is not already being
 392          * resumed, but no need to hold it due to initialized
 393          */
 394         spin_lock_irq(&intfdata->susp_lock);
 395         if (--intfdata->open_ports == 0)
 396                 serial->interface->needs_remote_wakeup = 0;
 397         spin_unlock_irq(&intfdata->susp_lock);
 398
 399         for (;;) {
 400                 urb = usb_get_from_anchor(&portdata->delayed);
 401                 if (!urb)
 402                         break;
 403                 unbusy_queued_urb(urb, portdata);
 404                 usb_autopm_put_interface_async(serial->interface);
 405         }
 406
 407         for (i = 0; i < N_IN_URB; i++)
 408                 usb_kill_urb(portdata->in_urbs[i]);
 409         for (i = 0; i < N_OUT_URB; i++)
 410                 usb_kill_urb(portdata->out_urbs[i]);
 411         usb_kill_urb(port->interrupt_in_urb);
 412
 413         usb_autopm_get_interface_no_resume(serial->interface);
 414 }
 415 EXPORT_SYMBOL(usb_wwan_close);
 416
 417 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
 418                                       int endpoint,
 419                                       int dir, void *ctx, char *buf, int len,
 420                                       void (*callback) (struct urb *))
 421 {
 422         struct usb_serial *serial = port->serial;
 423         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 424         struct urb *urb;
 425
 426         urb = usb_alloc_urb(0, GFP_KERNEL);     /* No ISO */
 427         if (!urb)
 428                 return NULL;
 429
 430         usb_fill_bulk_urb(urb, serial->dev,
 431                           usb_sndbulkpipe(serial->dev, endpoint) | dir,
 432                           buf, len, callback, ctx);
 433
 434         if (intfdata->use_zlp && dir == USB_DIR_OUT)
 435                 urb->transfer_flags |= URB_ZERO_PACKET;
 436
 437         return urb;
 438 }
 439
 440 int usb_wwan_port_probe(struct usb_serial_port *port)
 441 {
 442         struct usb_wwan_port_private *portdata;
 443         struct urb *urb;
 444         u8 *buffer;
 445         int i;
 446
 447         if (!port->bulk_in_size || !port->bulk_out_size)
 448                 return -ENODEV;
 449
 450         portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
 451         if (!portdata)
 452                 return -ENOMEM;
 453
 454         init_usb_anchor(&portdata->delayed);
 455
 456         for (i = 0; i < N_IN_URB; i++) {
 457                 buffer = (u8 *)__get_free_page(GFP_KERNEL);
 458                 if (!buffer)
 459                         goto bail_out_error;
 460                 portdata->in_buffer[i] = buffer;
 461
 462                 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
 463                                                 USB_DIR_IN, port,
 464                                                 buffer, IN_BUFLEN,
 465                                                 usb_wwan_indat_callback);
 466                 portdata->in_urbs[i] = urb;
 467         }
 468
 469         for (i = 0; i < N_OUT_URB; i++) {
 470                 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
 471                 if (!buffer)
 472                         goto bail_out_error2;
 473                 portdata->out_buffer[i] = buffer;
 474
 475                 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
 476                                                 USB_DIR_OUT, port,
 477                                                 buffer, OUT_BUFLEN,
 478                                                 usb_wwan_outdat_callback);
 479                 portdata->out_urbs[i] = urb;
 480         }
 481
 482         usb_set_serial_port_data(port, portdata);
 483
 484         return 0;
 485
 486 bail_out_error2:
 487         for (i = 0; i < N_OUT_URB; i++) {
 488                 usb_free_urb(portdata->out_urbs[i]);
 489                 kfree(portdata->out_buffer[i]);
 490         }
 491 bail_out_error:
 492         for (i = 0; i < N_IN_URB; i++) {
 493                 usb_free_urb(portdata->in_urbs[i]);
 494                 free_page((unsigned long)portdata->in_buffer[i]);
 495         }
 496         kfree(portdata);
 497
 498         return -ENOMEM;
 499 }
 500 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
 501
 502 void usb_wwan_port_remove(struct usb_serial_port *port)
 503 {
 504         int i;
 505         struct usb_wwan_port_private *portdata;
 506
 507         portdata = usb_get_serial_port_data(port);
 508         usb_set_serial_port_data(port, NULL);
 509
 510         for (i = 0; i < N_IN_URB; i++) {
 511                 usb_free_urb(portdata->in_urbs[i]);
 512                 free_page((unsigned long)portdata->in_buffer[i]);
 513         }
 514         for (i = 0; i < N_OUT_URB; i++) {
 515                 usb_free_urb(portdata->out_urbs[i]);
 516                 kfree(portdata->out_buffer[i]);
 517         }
 518
 519         kfree(portdata);
 520 }
 521 EXPORT_SYMBOL(usb_wwan_port_remove);
 522
 523 #ifdef CONFIG_PM
 524 static void stop_urbs(struct usb_serial *serial)
 525 {
 526         int i, j;
 527         struct usb_serial_port *port;
 528         struct usb_wwan_port_private *portdata;
 529
 530         for (i = 0; i < serial->num_ports; ++i) {
 531                 port = serial->port[i];
 532                 portdata = usb_get_serial_port_data(port);
 533                 if (!portdata)
 534                         continue;
 535                 for (j = 0; j < N_IN_URB; j++)
 536                         usb_kill_urb(portdata->in_urbs[j]);
 537                 for (j = 0; j < N_OUT_URB; j++)
 538                         usb_kill_urb(portdata->out_urbs[j]);
 539                 usb_kill_urb(port->interrupt_in_urb);
 540         }
 541 }
 542
 543 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
 544 {
 545         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 546
 547         spin_lock_irq(&intfdata->susp_lock);
 548         if (PMSG_IS_AUTO(message)) {
 549                 if (intfdata->in_flight) {
 550                         spin_unlock_irq(&intfdata->susp_lock);
 551                         return -EBUSY;
 552                 }
 553         }
 554         intfdata->suspended = 1;
 555         spin_unlock_irq(&intfdata->susp_lock);
 556
 557         stop_urbs(serial);
 558
 559         return 0;
 560 }
 561 EXPORT_SYMBOL(usb_wwan_suspend);
 562
 563 /* Caller must hold susp_lock. */
 564 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
 565 {
 566         struct usb_serial *serial = port->serial;
 567         struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
 568         struct usb_wwan_port_private *portdata;
 569         struct urb *urb;
 570         int err_count = 0;
 571         int err;
 572
 573         portdata = usb_get_serial_port_data(port);
 574
 575         for (;;) {
 576                 urb = usb_get_from_anchor(&portdata->delayed);
 577                 if (!urb)
 578                         break;
 579
 580                 err = usb_submit_urb(urb, GFP_ATOMIC);
 581                 if (err) {
 582                         dev_err(&port->dev, "%s: submit urb failed: %d\n",
 583                                         __func__, err);
 584                         err_count++;
 585                         unbusy_queued_urb(urb, portdata);
 586                         usb_autopm_put_interface_async(serial->interface);
 587                         continue;
 588                 }
 589                 data->in_flight++;
 590         }
 591
 592         if (err_count)
 593                 return -EIO;
 594
 595         return 0;
 596 }
 597
 598 int usb_wwan_resume(struct usb_serial *serial)
 599 {
 600         int i, j;
 601         struct usb_serial_port *port;
 602         struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 603         struct usb_wwan_port_private *portdata;
 604         struct urb *urb;
 605         int err;
 606         int err_count = 0;
 607
 608         spin_lock_irq(&intfdata->susp_lock);
 609         for (i = 0; i < serial->num_ports; i++) {
 610                 port = serial->port[i];
 611
 612                 if (!tty_port_initialized(&port->port))
 613                         continue;
 614
 615                 portdata = usb_get_serial_port_data(port);
 616
 617                 if (port->interrupt_in_urb) {
 618                         err = usb_submit_urb(port->interrupt_in_urb,
 619                                         GFP_ATOMIC);
 620                         if (err) {
 621                                 dev_err(&port->dev,
 622                                         "%s: submit int urb failed: %d\n",
 623                                         __func__, err);
 624                                 err_count++;
 625                         }
 626                 }
 627
 628                 err = usb_wwan_submit_delayed_urbs(port);
 629                 if (err)
 630                         err_count++;
 631
 632                 for (j = 0; j < N_IN_URB; j++) {
 633                         urb = portdata->in_urbs[j];
 634                         err = usb_submit_urb(urb, GFP_ATOMIC);
 635                         if (err < 0) {
 636                                 dev_err(&port->dev,
 637                                         "%s: submit read urb %d failed: %d\n",
 638                                         __func__, i, err);
 639                                 err_count++;
 640                         }
 641                 }
 642         }
 643         intfdata->suspended = 0;
 644         spin_unlock_irq(&intfdata->susp_lock);
 645
 646         if (err_count)
 647                 return -EIO;
 648
 649         return 0;
 650 }
 651 EXPORT_SYMBOL(usb_wwan_resume);
 652 #endif
 653
 654 MODULE_AUTHOR(DRIVER_AUTHOR);
 655 MODULE_DESCRIPTION(DRIVER_DESC);
 656 MODULE_LICENSE("GPL v2");